Incandescent electric lamp



Oct. 18, 1955 V N. J. RAINONE 2,121,291

INCANDESCENT ELECTRIC LAMP Filed Feb. 27. 1953 /35 5 -42 I 51A /5z E fiiBY 2 ATTORNEY United States Patent 1 INCANDESCENT ELECTRIC LAMP Nicholas J. Rainone, Clifton, N. J., assignor to- Westinghouse Electric Corporation, East Pittsburgh, Pa., a cor poration of Pennsylvania Application February 27,; 1953, Serial. No. 339,328

4 Claims. (Cl. 313-276) complished by arranging the filament coils a single ordouble vertical plane, accurately located with respect to the optical system, as by a prefocu's base. The biplane filament, with coils. arranged in: two rows so that the coils in the one row fill in the spaces between those" of the other, has much greater uniformity and higher average brightness than the single row monoplane filamen't. Projection lamps have such small bulbs and opcrate at such high temperatures that they can not be burned without continuous forced ventilation to cool the bulb;

Hence, it has been found advantageous according to myinvention to provide an improved replaceable floating; bridge for a projection lamp which can be made on an automatic inserting machine with ahigh? production rate, reduced shrinkage, and improved quality. The four supports and three guides are inserted in spaced holes, arranged in a single plane, in a suitable block or" guide. A vitreous cane insulator is positioned on topof the projecting ends of saidsupp'orts and guides in a suitable groove therein. 7 a semi-plastic condition and the formed end of a plunger pushes the cane onto the projecting end'portions of the supports and guides.

This apparatus provides more uniform spacing of the supports and guides, reduces the hand labor and shrinkage,- produces fewer cracks during mounting and fewer burned supports and guide wires" during manufactureof the floating bridge;

The ends of the guides and the supports are thensuitably formed, as hereinafter explained, on an automatic fixture to permit the insertion of the floating guide of my invention into place on the inner supporting leads either as an original floatingbridge for a* lamp mount; or as a replacement for a cracked bridge without 'disturbing the other assembled mount parts;

Inits. general aspect the present invention has as 'its' objective the elimination of the defects off the prior 'a-r't mount construction for a projection lamp.

A specific object of the present invention is an improved replaceable floating bridge for projection lamps Fires then heat the came to 2,721,291 Patented (lot. 18, T955 ice An additional object is a replaceable bottom floating bridge for a projection lamp having the supports and guides aligned in asingle plane.

A still further object is a replaceable bottom floating bridge for a projection lamp which is more readily mountable on the supporting leads of the lamp mount and is removable therefrom without disturbing or removing the other mount parts. v

Other objects of the present invention will appear to those skilled in the art as the description thereof p'roceeds.

Referring to the drawing in which like numerals of reference indicate similar parts throughout the several views:

Fig. l is a side elevational' View of a projection embodying the improved replaceable floating bridge of Fig. 5 is a sectional view along the lines V-V o Fig. 5 in the direction of the arrows.

Fig. 6 is perspective view of the improved floating bridge of my invention after bending and forming of the guides and supports.

Referring to the drawing and particularly to Fig. I' an improved projection lamp of my invention is designated by the reference numeral 10. This projection.

la'r'np' may comprise a tubular envelope 12 with a base I4fand a mount. 16. I

This mount 16 has a vitreous stem 18 which is sealed to the bulb 1 2 and is provided with leading-in and supporting conductors 20 and 22 and a center spud 24 projecting from a p ess 26 thereof. In the presentv embodim'entthe normally free ends of thesesupporting conductors 20 and 22' are bent at right angles, as illus trated, for mounting thereon, the outer supports 24" of a' fixed top bridge 26. These supports 24" and a plurality of upper filament supports 28, three in theYp-resent showingof Figs. 1 and 3', depend from an insulator 30', suitably apiece of glass cane, of the top bridge 26'. The" lower hooked ends of the supports 28 are in en gage'm'ent with the top interconnecting loops of a fila-v them" 32, handily comprising in the present showing;

' carrying coils thereon for threading onto legs of the. filamerit 3 2. These inserts 34 and 36 are suitably bentfo r welding to the leading-in and supporting conductors 20 and 22" near their upper bends. Animproved replaceable lower floating bridge 40 (Fig. 6) of my invention having arr insulator 42,. bottom filament supports 43-, d4,v 45,, 46, side" guides 47 and 48' and a bottom guide 50, supports the'botto'm' loops of the filament 32 and slidably engages the conductors 20 and- 22 and the spud 24 as hereinafter explained.

Improved replaceable flaming 'bridge' To-' fabricate the replaceable floating bridge of invention the straight bottom filament supports" 43 to 46, side guides 47 and 48', and bottom guide 50- arein'se'rted in spaced holes aligned in a vertical plane of a wire insetting head riot shown. The depth of these holes is predetermined so that an equal portion of each of the supports and guides projects above the upper end' of each hole; Two extensions on the upper end of theb'loc'k are provided with inner vertical guide grooves" for guiding the insulator 42 onto the upper extremities of the supports and guides.

A flame, directed preferably at the under side of the insulator 42, plasticizes this portion of said insulator for the wire inserting operation. At the appropriate moment a cam actuated plunger having a longitudinal forming groove cut therein and contoured to the shape of said insulator, contacts and secures the insulator in the forming groove. Simultaneously the plunger pushes the supports and guides into the plastic section of the insulator and also forms or retains the generally cylindrical form of said insulator.

After the bridge 40 has been properly annealed and cooled it is transferred to an automatic bending and forming fixture not shown. As shown in Fig. 6 the upper or free end of the side guides 47 and 48 are bent outwardly from the supports 43 to 46 and have a U-shaped horizontal hook 51 and 52 respectively formed thereat. These books 51 and 52 are of suflicient width to freely clear the leading-in and supporting conductors 20 and 22 on which they slide. In like manner a V-like hook is provided in each of the supports 43 to 46. The bottom guide 50 is bent backwardly and downwardly away from the supports 43 to 46 as shown in Fig. 4 into a generally C-shaped configuration and has a loop or eye 54 provided in its lower depending extremity. It will be understood that the center of the eye 54 is appropriately axially aligned in the plane of the guides 47 and 48 and the supports 43 to 46.

Mounting To make the mount 16, the loops 51 and 52 in the side guides 47 and 48 of the floating bridge 40 are slid over either the top portions or the bottom portions of the leading-in and supporting conductors 20 and 22 so that the loop 54 in the now formed lower guide 50 can be passed over the now straight center spud 24. The floating bridge 40 is then permitted to hang in its lowermost position.

The stem 18 may be clamped in a suitable mounting fixture not shown by securing brackets placed over the lower curved portions of the leading-in conductors 20 and 22. The lower loops of the filament 32 which has already been provided with suitable bent connectors 34 and 36 are secured on the upper hooks of the supports 43 to 46.

The filament 32 is then located in the filament positioning nest on the mounting fixture, thus insuring a correct light center length for the lamp 10. The depending hooks of the supports 28 of the top bridge 26' are inserted through the top loops of the filament 32 and the supports 24 of the top bridge 26' are welded to the upper bent ends of the leading-in and supporting conductors 20 and 22. Simultaneously the filament leg connectors 34 and 36 are similarly secured, as by welding, to the conductors 20 and 22. The operator pulls downwardly on the floating bridge 40 with suflicient force to pull the filament 32 taut without applying excessive or breaking tension thereto. When the proper tension is acquired, the operator forms a right angle bend 56, Figs. 4 an 5, in the upper or free end of the center spud 24, thus locking the filament with the desired tension in the non-operative condition.

Replacement mounting In the event that a cracked insulator 42 should develop in the floating bridge 40 it is relatively simple, according to my invention, to replace the defective bridge 40 without removing or disturbing the other already assembled above mentioned parts. The bent portion 56 of the spud 24 is returned to its original vertical position. The upper hooks on the supports 43 to 46 are withdrawn from the bottom loops of the filament 32. The defective bridge 40 is then removed from the mount 18 by cutting therefrom or by sliding the eye 54 over the end of the spud 24 and sliding downwardly the hooks 51 and 52 on the end guides 47 and 48 over the lower portions of the leading-in conductor 20 and 22.

As shown in Fig. 3 a new floating bridge 40 is then positioned between two fingers of the operator adjacent the bottom bent portions of conductors 20 and 22. The hooks 51 and 52 are inserted around the conductors 20 and 22, and moved upwardly thereon a suflicient distance to permit passage of the eye 54 in the lower guide 50 over the now straightened portion of the center spud 24.

It will be understood that although the upper portions of the filaments 32 are rigidly secured to conductors 20 and 22 by means of connectors 34 and 36 and the top bridge 30, the lower unconnected portions of the filaments 32 are sufiiciently flexible within the nest of the mounting block to permit movement of the bottom portion away from the mount axis without permanent deformation of the filament 32. It will further be understood that the bottom guide 50 and the center spud on which it is now slidably engaged are sufliciently small in diameter and hence flexible enough to permit lateral movement of the hooks of the upper ends of the supports 43 to 46 away from the vertical axis of the mount 18. Again, the hooks 51 and 52 on the side guides 47 and 48 are provided with suflicient clearance between themselves and the conductors 20 and 22 to permit a pivotal movement of the replacement bridge 40 thereon and to allow the insertion of said hooks in the lower loops of the filament 32, which may be extended laterally away from the filament nest to permit such insertion.

As before, the replacement bridge 40 is pulled downwardly by the operator sufliciently to pull the filament 32 taut. The upper end 56 of the center spud 24 is bent forward horizontally to secure the filament 32 with a desired tension when the lamp 10 is in the cold state.

Although a preferred embodiment of my invention has been disclosed it will be understood that modifications may be made within the spirit and scope of the invention.

I claim:

1. An incandescent electric lamp adapted for projection service comprising an enclosing envelope and a lamp mount sealed to said envelope, said mount having a stem provided with leading-in and supporting conductors, and a center spud, a fixed top bridge on the upper ends of said conductors, said bridge having a plurality of top filament supports, each provided with a hook in the lower depending end, a filament fixed on said conductors and said upper supports and a replaceable floating lower bridge in slidable engagement with said leading in conductors and said center spud and in holding engagement with said filament, said floating bridge having an insulator provided with a pair of side guides engaging said conductors, each of said side guides having an outwardly extending bend in the free end thereof, said free end being provided with an open ended hook, a center bottom guide slidably engaging said center spud and a plurality of lower filament supports disposed between said center guide and each of said side guides holding said filament, each of said supports and said guides having one extremity inserted in'the side wall of said insulator and aligned in a single vertical plane.

2. An incandescent electric lamp adapted for projection service comprising an enclosing envelope and a lamp mount sealed to said envelope, said mount having a stem provided with leading-in and supporting conductors, and a center spud, a fixed top bridge on the upper ends of said conductors, said .bridge having a plurality of top filament supports, each provided with a hook in the lower depending end, a filament fixed on said conductors and said upper supports and a replaceable floating lower bridge in slidable engagement with said leading-in conductors and said center spud and in holding engagement with said filament, said floating bridge having an insulator provided with a pair of side guides engaging said conductors, each of said guides having an outwardly extending bend in the free end thereof, said free end being provided with an open ended hook, a center bottom guide slidably engaging said center spud, said center guide being generally C-shaped in configuration and having a loop provided in its lower depending extremity, and a plurality of lower filament supports disposed between said center guide and each of said side guides holding said filament, each of said supports and said guides having one extremity inserted in the side wall of said insulator and aligned in a single vertical plane.

3. A floating bridge for a projection lamp having an insulator provided with a pair of side guides, each of said side guides having an outwardly extending bend in the free end thereof, said free end being provided with an open ended hook, a center bottom guide, and a plurality of filament supports, disposed between said center guide and each of said side guides, each of said supports and said guides having one extremity inserted in the side wall of said insulator and aligned in a single vertical plane.

4. A floating bridge for a projection lamp having an insulator provided with a pair of side guides, each of said guides having an outwardly extending bend in the free end thereof, said free end being provided with an open ended hook, a center bottom guide generally C-shaped in configuration and having a loop provided in its lower depending extremity, and a plurality of filament supports disposed between said center guide and each of said side guides, each of said supports and said guides having one extremity inserted in the side wall of said insulator and aligned in a single vertical plane.

References Cited in the file of this patent UNITED STATES PATENTS 2,462,325 Leighton Feb. 22, 1949 2,605,440 Gero July 29, 1952 2,644,102 Stone June 30, 1953 

